Encapsulation of Pd Nanoparticles in Covalent Triazine Frameworks for Enhanced Photocatalytic CO<sub>2</sub> Conversion
Shien Guo, Yuting Xiao, Baojiang Jiang
Abstract
Photoreduction of CO2 into solar fuels is an appealing solution to simultaneously mitigate environmental problems and energy crisis, but photocatalyst activity and product selectivity remain challenging. Herein, ultrafine Pd nanoparticles immobilized in an imine-linked covalent triazine framework (Pd@Imine-CTF) are successfully prepared via a wet-chemistry approach. The resultant Pd@Imine-CTF exhibits a highly porous structure, which exposes more active sites and promotes CO2 adsorption and diffusion for photocatalysis. The ultrasmall Pd nanoparticles are confined and stabilized because of the strong interaction between Pd and pyridinic nitrogen atoms within Imine-CTF, which is beneficial for boosting the charge carrier separation and providing ideal sites for CO2 reduction reactions. Under visible-light irradiation, Pd@Imine-CTF displays excellent photocatalytic performance toward CO2 reduction, yielding CO and CH4 with evolution rates of 85.3 and 21.1 μmol g–1 h–1, respectively, and with a remarkable selectivity of up to 91.8%. This work provides a new protocol for the rational design of CTF-based photocatalyst composites for efficient CO2 conversion.